Articles formed of solid or semi-solid polymers frequently have surface characteristics that detract from and at least partially offset the advantages of the bulk properties of the polymers. In the past, such deficiencies have sometimes been reduced by applying surface coatings or treatments, or by utilizing protective packaging. For example, latex articles used for medical purposes may be coated with lubricants to reduce frictional resistance, hermetically packaged to retard deterioration and pinhole development, powdered to reduce blocking, etc. Such measures often create additional complications and risks, and are not always effective or even applicable. Thus, coating a latex catheter with a lubricant jelly to reduce friction not only imposes an undesirable burden on the medical practitioner or user but creates additional risks of contamination, possible bio-incompatability, interferences with catheter porting and operation, and the like.
The prior art discloses various chemical reactions in which fluorocarbon entities have been grafted to polymers; however, in such reactions the polymers have generally been in solution during treatment and the resulting products have been substantially homogeneous in composition. Applicants are unaware of prior teachings in which an article composed of a preformed solid or semi-solid polymeric substrate is grafted only along one or more of its surfaces to acquire the surface properties of a fluorocarbon while simultaneously retaining the bulk properties of the polymeric substrate. Reference may be had to the following patents of interest: U.S. Pat. Nos. 3,322,721, 3,842,053, 1,826,275, 2,005,320, 3,480,609, 3,714,297, 3,332,812, 3,340,281, 3,351,663, 3,369,012, and 3,480,549. Certain of these references (U.S. Pat. Nos. 1,826,275, 2,005,320, 3,480,609, 3,714,297) are of additional interest because they disclose the epoxidation of synthetic or natural rubber, although such references are concerned more with the compounding of rubber and do not disclose grafting processes for converting only the surface of a preformed solid polymeric substrate.